Drilling bit



Jan, 26, 1932. V5.1. KulN ETAL ,1,843,096

DRILLING BIT Filed Feb. 7, 1929 l /6 y@ 'WQM/ Patented Jan. 26, 1932 41tilsiiren STATES PATENT OFFICE;l

A vAiSiJ. Konin, or BREA'AND rnnRY rUNijnRBUnxfoi-i FULLERTON, cALironmA, As`

n sieivoasroi oHiKsAN OIL ToOLOO., LIMITED', A CORPORATION orv NEVADA vnarrante k131i1 4 Application led February 7, 1929. Serial No. 338,084.

This invention relates toa rotary vdrill and relates particularly/'to a-drill for use in drilling Wells with the rotary method.

. -It lhas been found that cutters of rotary- 5 well vdrilling bits, and especially the disk type of cutters, `wear rapidly during drilling op.

Yerations.'V As the cutters wear, they become reduced in size or diameter, and fail to cut or drill'a'holerof the desired size.

provide a rotary drill in which the cutters Will not readily mud up. The cutters in the present drill arearranged in pairs and the'cutters of reach pair work relative to each V other. so thatv they Vkeep themselvesclean.

It is another objectof the invention to provide a rotary drill in which lcertain Vcutters engage the bottom Y of thev hole while the Y other cutters on the same mountings engage Vonly the wall of the hole. j

' It is another obfect of the invention to provide vapdrill of the character mentioned in which a plurality of` cutters are mounted on the same pin so that they rotate eccentrically 2?` andl independently of one another.

The various objects and features of our invention will be best and more fully understood 'from the following detailed rdescription 4of a typical A.preferred formofrthe invention, throughout lwhich descriptionreference is had to the accompanying drawings, in which: 4 u A y Figl is a side elevation of the device provid-ed by this invention. Fig. 2is a bottom plan. ,view showingthe relative positions of the cutters in the preferred form of the iiivention. Fig. 3 is an enlarged ldetailed sectionalview taken as indicated by line 8-73 on Fig.,1, and Fig. 4 is an enlarged detailed 4o sectionalvie'w taken as indicatedk by line Ll-Yl OnFig.3. f'

The drilling bit provided by this invention includes, generally, a bod7 or shank portion v10 having a screw-threaded pin11 at its upper end for connection with a string of drill pipe, a plurality of spaced arms 12 and 13 arranged in pairs and projecting from the lower end of the shank portion, bushings 14 mounted between each pair of arms 12 and 13, pins 15 carriedby ami extending between the arms 12 It is aprimary object'of this invention to and 13 of each pair and operating to carry the bushings, and disk cutters 16 rotatablycarried on the bushings. Y. f

The shank portion 10 vis elongated andfis preferably round in cross section. In the form of the invention illustrated in the drawings the shank is provided near its upper end with an enlargedpart forming a downwardly facing shoulder 17 adaptedto be engaged by a fishing tool toY facilitate lthe removal of the bit from a well bore in'the event the bit becomes -lost in the well. :The pin 11 projects from the upper end of the'shank 10 and is v tapered and screw threaded as shown in the drawings. A fluid circulation opening 18 eX- tends longitudinally through the shank :and

discharges at the center of the lower end of the shank portion. The lower end of the opening 18 is provided with a detachable nozzle bushing 19 preferably screw threaded into the lower end of the opening.

-The arms .12 and 13 extend and radially from the lower end of the shank portion 10 and are preferably formed integral with the shank portion. In the form of the inventionillustrated the lower end of the shank 10 is enlarged so that the arms 12 and i downwardly v 13 are'readily :formed integral with the shank and are of relatively heavy and sturdy construction. The arms are in pairs, each pair including an upper arm 12 and a lower arm There may be any desired number of pairs of arms. In the preferred form of the invention shovvnvwe provide three pairs of arms symmetrically disposed around the central .longitudinal axis of the bit.- The pairs of arms 12 and 13, being equally spaced I and symmetrically disposed around the central longitudinal axis of the shank 10, carry the cutters 16 so that theyoperate to center the bit inthe well bore during operation. The arms 12 and 13 are in spaced parallel relation to each other and are similarly disposed with relation to the central longitudinal axis of the shank.

In practice we prefer to pitch the arms at approximately 45 degrees with reference to the vertical axisof'the bit. rFhe lower ends of theA arms may bev beveled or dressed off to lower arms 13 are preferably beveled as shown at 20 in the drawings to be at approximately 90 degrees to the vertical axis of the shank 107 while the lower end of the upper arm 12is beveled as at 21 so as to be substantially parallel -to the vertical axis of theshank 10.' VViththis beveling of `the arms,

' there is ample clearance for the passage ofY cuttings andY circulation fluidgr'llhe `0uter j. edges ofthe-'farms may bri-alsobeveled asy shown inthedrawingsto further prov-ide for theipassage of cuttings and circulation fluid.

The kbushings 14 are carried on the pins 15 A between the pairsof armstocarry the cutters 16 sothat they are'disposed between the arms 12and .13 andl in. planes parallel tolthose of the-Larme. The :cutters have: their V cutting edges extending downwardly and radially outward beyondlthe floweriendsand sides of 20ffthearms to -engageizthe vbottom andthe side wallsfo'fetheiwell .bore.`f.l In accordance with'. .the broad: spiritof the invention there may be a unitary 'bushingY `member `:disposed between 3Ofabut. or bear on each other whileA their outer sides 22flengagef the inner surfaces 23-andI 24' kofy the. arms: -12 'fa-nd 1.13,? respectively?. Each bushingfisprovidedavithl an exterior cylindri-Vv Y ca-l bearing'surface 25y to rotatably carryacutl 35.@ter-andris lprovidedfat itsouter -endfwith a i radially projecting-.flange 12. The iianges'f 12b operate torsp'ace the cutters tmmfhg, inner faces y23 fand 24-of 'the' arms.y r The bushings are mountedstationaryfor held against move'- i2nientsrelat1ve to the farms, lso 'that vall` wear,

corresponding recesses or.v slots 30 inthe inner faces 23 andf24 of the arms. The key-parts v are. dis-posedso `that thebushings-canbe easilyA slidintoplace .betweenA the-armsV and operate I to {posit-ivelyfprevent rotation of thebushings when. the:l bushings tare ,in operatin g position.

The. bushings aref-mounte'd-'on pins 15r` which'vv extendthroughand between the arms 12 .and 13.v The pins extend through openventionf shown. inthe drawings the eccen tricity ofrthe 'openings 46isthe same inall y of :the v bushings; The' twol bush-ings' between .ings;46`inf thebushings.l The axes of the openings 46fare offset orreccentriclto thebearing'surfacesf25'. The eccentricity ofv the f k pair of' arms may .be substantially the same or may vary or be different as circumstances porting pin 15 so the cutter carrying Ybearing surfaces are offset in differentdirections from the axis of the pin. In the preferred arrangement illustrated' the two bushings are mounted on the pin'15 so that the axes of the bearing-surfaces 25. are Oifset in diametrically oppositedirections. It is advantageous to arrange the'bushings so that thelower bushing v.is offset downwardly, andthe upper bushingfxoffset upwardly. .y

This' throws the lowermost cutter yof `each pair ofcutters downwardly so that it is well below the upper cutter and therefore does the cuttingon the bottom of the hole. The upper cutter is clear ofv the bottom of the hole butV projects radially outward. and is located above thelower cutterso that it-vcuts..

the sideiofthehole, keeping'the holeto gauge. The cutters arev free to rotate'independently of one another on the bushings and during operation they move or work rela.-KV

thatthey do not become tive-toeach other so muddedup.

pin isprovided with a polygonal/head 36 The pin 15iextendsthroughan opening 34e which seats Aagainst the outer side of the upper arm Vl2. In the'l constructionprovided by this invention .the pin'15has notendency to rotate Yand thus becomelloosened ordisengaged! from the threaded 'opening 35. TheA pinl may be locked orfurther secured. by

suitablemeans, if so desired. f

The cutters 32 and 33 are disk type cutters' each having-fa central 'opening-37 to `receive d v Y 5 38 of each upper cutter is beveled oiffat sub` due to "the .rotati'onfl ofthe cutt-e r,-l occurs be-v y tween thecuttersjand thebushings. :Int-he forlm of lthe zinventiion' illustrated. the outer ends yofthebu'shings are providedwith trans- Y t""verser projectingkey parts 261which fit into*` stantially 45 deofrees to forma cutting edge.

and forms. a cutting edge 41. The lower cut? ter normallyengages the bottom'` of thefwell bore andthe edge 41 is inposition Vto effectivelygcut the formation at the bottom of the Y bore..l

In the preferred construction thecutters are counter bored at 85 so vthat the bushings seat in the cutters. This gives the. cutting partsmaximum clearance'and permits the use of. thick cutters. f

' Having described one pair `of arms and the'bushings7 pin, andcutters carried by the arms, it 1s apparent that such description ap plies to each cutter unit Aembodied in the bit. It will be `apparent .that ,suchFcu'tter assemblies, symmetrically arranged as illustrated7 provide `a bit which -isfsimple, effective,v andl practical. It is to be particularly noted that the upper cutters and the lower cutters of the several pairs of cutters operate to separately cut the wall of the well and the bottom of the Well, that is,the upper cuttersl engage only the walls of the well while the lower cutters engage principally the Vbottom of the well. The lower cutters may wear more rapidly than the upper cutters and become smaller indiameter than the upper cutter and thus drill a hole of reduced diameter, however, as the bit is fed downwardly the upper cutters engage the wall of the hole and cut it to the desired size. As the lower cutters become worn, the upper cutters take a larger cut.

Having described only a typical preferred Aform of our invention, we do not wish to limit ourselves to the specilic details set forth, but wish to reserve to ourselves any changes or variations that may appear to those skilled in the art or fall within the scope of the following claims:

' Having described our invention, we claim: 1. A well drilling bit including, a shank, spaced arms projecting from the shank, bushings mounted between the arms, the bushings being held against rotation, each bushing having a cylindrical bearing part, and cutters rotatably mounted on the bearing parts so that they are inclined with reference to f the longitudinal axis of the shank, the axes of said bearing parts being spaced apart and parallel with each other.

2. AV well drilling bit including, ashank, spaced parallel arms projecting downwardly and radially from the shank, two bushings mounted between the spaced arms the bushings having cylindrical bearing parts, a pin extendingA between the spaced arms and through the bushings eccentric to the bearing parts, means holding the bushings against rotation so that the axes of the bearing parts are diametrically opposite, and cutters rotatk ably mounted on the bushings.

3. A well drillingbit of the character describedV including, a shank, a plurality of symmetrically arranged pairs of spaced arms projecting downwardly and radially from the shank, two bushings arranged between each pair of arms,.each bushing having an f exterior cylindrical bearing surface, a pin projecting downwardly fand radially froinf; the shanky andinclined relative tothe-,fver, tical axis of the shank,`two .bushingsfar--z ranged between each rfpaii; of! arms,` the. :bushf ings having cylindrical l bearing-;parts, pinsy carried: .by the arms-,andextendingthrouglr;

openings :in the bushings, the openings be.

ing eccentric to the bearing parts, the bush?,A

ings beingfrarranged so that tlle'bearingpalts of the two` bushings .arranged between;r each,v

pair of arms arefeccentricfto 'each other',-y

v bearing parts on the bushings, a pin carried by the arms exten'ding'through openings in the bushings eccentric to the bearing parts, means holding the bushings against rotation, and holding them so that their bearing parts are oppositely disposed, an upper cutter rotatably mounted on one bearing part, and a lower cutter rotatably mounted on the other bearing part, the cutters being in engagement with each other.

y6. A well drilling bit including, a shank, spaced arms projecting downwardly and radially from the shank, vupper and lower bushings arranged between the arms, each bushing having a cylindrical bearing part, a pin carried by the arms extending through openings in the bushings eccentric to the bearing parts, an upper cutter' rotatably mounted on the bearing part of the upper bushing, and a lower cutter rotatably mount! ed on the bearing part of the lower bushing, the periphery of the lower cutter being beveled so that its leading part is. substantially vertical and the periphery of the upper cutter being beveled so that its leading part is substantially horizontahand means holding the bushings so that the bearing parts are eccentric to each other.

7. A well drilling bit including, a shank, spaced arms projecting from the shank, bushings mounted between the arms, means holding the bushings against rotation, a cylindrical bearing part on each bushing, the axesgv of said bearing parts being spaced apart and parallel with each other, cutters rotatably mounted on the bearing parts so that they are inclined with reference to the vertical axis of the shank, and flanges on the bushings spacing the cutters from the arms, the flanges being recessed in the cutters.

8. A well drilling bit of the character described, including` a shank, spaced arms on the shank, bushings carried between the arms and having cylindrical bearing parts, a pin extending through the arms and through openings in the bushings, the openings in the bushings being eccentric to the bearing parts, means holding the bushings against rotation so fha# thelbearing parts are' `eccrn-Y 1 tric toeach otherysaid Vmeans; vincluding' a transverse key-projection on each loushng,V

rd byf the bearing parts and" inclineld with reference to the longitudinal axis of the shank. I: Y

-W fhavehereunto subscribed our;` names YthisV 

